[hatzie]

Originally Posted by TooTall

With your stock engine, you will have zero issues with "shocking" the trans. You can copy over the line pressure setting from the tow-haul or performance tables to the normal tables.
If you're wanting to make the trans run cooler, shorten the shift timing, and add an inline trans cooler like a Tru-Cool Max 40GRW.
If you ever feel a laggy 1st gear start after coming to a stop. There's a fix for that, and TransGo sells a piston replacement kit for it.

I can just push the tow-haul button to get that. I want to put some miles on it to see if the original GM settings are too sloppy for my taste with the proper tire sizes in the PCM now.

Already have the Tru Cool 40K plate cooler mounts along with the Delco Jiffy-Tite transmission line adapters. Just need to put it in.

1st gear in my 4L80 is still pretty tight right now.

Originally Posted by TooTall

I used the same Merchant Auto kit on my replacement tcase and it was painless. I bought everything from them as a kit.The hardest part was pulling and installing the TCase while as you said, on the cold concrete. I spent some time getting all of the original RTV out of the case along with the sludge build up around the filter area.

That's the direction I'm leaning on the kits. It'll be nice to clean the crud out of the bottom of the case too. The Howto videos show removing the magnet and replacing it with a smaller one on the drain plugs... Not a good idea IMHO. It looks like it's the same big Allison filter donut magnet GM called for in the 4T65E and 4L60E transmission magnet TSB. The Allison magnet is rated for more than 300°F with a lot of surface area to pick up iron particles from the silent chain... that's probably what I have in my NP263HD so it's staying after a good cleanup.